I have this idea that map-connection lines should originate within the map that they are defined in, and end within the submap that is offset.  In other words, that they should follow the vector that describes the offset local to the map that they are defined in.  Similarly, previews (explicitly defined as well as when the result of an offset). Exactly as shown in the Therion Book.

What I am finding is that the map-connection lines originate in the map that is selected in the th-config, and end within the submap that is offset.  When there is more than one level of offset this means that they follow the sum of all offset vectors.  In addition, previews that are the result of an offset are not local to the map they are defined in, but appear in the selected map (explicitly defined previews seem to be OK though).

Quite possibly I am doing something wrong, but it escapes me.

The above is the gist of mu dilemma really.  What follows is just more tedious detail…

I am trying to create a plan map of a vertical cave, where each of the submaps have a map-connection line between them.  I am planning to export them to a map (I’m not thinking of atlas at this stage).

Juraj Halama showed us an example last year

And explained how to get the submap to submap map-connection lines, as well as the overall (radial selected map to submap) map-connection lines in this post.

https://www.mail-archive.com/therion@speleo.sk/msg08318.html  It seems to have about the right level of complexity to achieve two sets of map-connections, but too much for a typical single set of map-connection lines.

I am looking for only submap to submap map-connections, as shown in the Therion Book, and the example suggests that this is the norm.

And so I am using syntax that I hope is like this…

and

And select m123 in my thconfig.

But alas I am only getting radial offsets from the ‘selected’ map.

My hope is that the pattern shown in the Therion Book can be nested without limit, but I have only ever been able to nest it two levels successfully as with the Therion Book (although just now I cannot even do that for some reason – but it did work a year ago when I last tried)

Once a third level is introduced the offsets go radial from the selected map, and not submap to submap.

The diagram below shows my map names with three levels of offsets (offset of offset of offset).  It also compares the  map-connection lines that I get, compared with what I expect. In all cases the thconfig only selects LaghuPlanMap.

When I am done, I think this particular project will require 8 to 10 levels of offset, so I am hoping there will be an easy pattern to follow.

An example: Offset of offset – These definitions produce the maps below…

map LaghuPlanMap -title "Laghu Cave Plan, Mt Arthur"                              like m123 in Therion Book example

#select this map when exporting a pdf plan with offset maps

    9-LaghuPlan-surface@Laghu #entrance pit                                                 like m1 in Therion Book example

    Laghu #survey centreline

    LaghuPlanMap-1over2 [-050 000 m] below #top level offset map              like m23 in Therion Book example

endmap LaghuPlanMap

map LaghuPlanMap-1over2 #next level down, midP3                                   like m23 in Therion Book example

              LaghuPlanMap-1                                                                                    like m2

              LaghuPlanMap-2  [000 020 m] below # next offset level                like m3

endmap

map LaghuPlanMap-1 #top level offset map                                                   like m2

    preview above 9-LaghuPlan-surface@Laghu

              9-LaghuPlan-underground@Laghu   # point map-connection in here plots correctly in offset level one

              7-LaghuPlan-upperP1P2@Laghu

              7-LaghuPlan-midP2P3@Laghu

              preview below LaghuPlanMap-2                                                         like m3

endmap

 map LaghuPlanMap-2 #next level down, midP3                                            like m3

              7-LaghuPlan-midP3@Laghu   # point map-connection plots incorrectly in offset level two

endmap

I can see that select xxx -map-level 1, 2 and 3 etc have an incremental and negative effect on the display of passage previews, but I don’t understand the guidance in the Therion Book on this. 

“preview <above/below> <other map id> will put the outline of the other map in the specified preview position relative to the current map.
Preview is displayed only if the map is in the map-level level as specified by the select command.
Use the revise command if you want to add maps from higher levels to the preview.”

So I am not using -map-level in these examples, and it seems to interfere with the offsets anyway.  I’m not sure if revise would help, or how to use it, but expect it might have some use with previews that appear in the wrong position.

Any insights appreciated.

Bruce